1. Field of the Invention
This invention relates to modular conveyors. In one of its aspects, the invention relates to a conveyor which is formed by joining modules end-to-end. In another of its aspects, the invention relates to a modular conveyor with radius turn modules. In yet another aspect, the invention relates to a method of assembling the radius turn module.
2. Related Art
Conveyor systems are commonly used for a variety of applications. Illustrative applications are: manufacturing facilities, assembly facilities, inventory distribution centers, and parcel or package distribution systems. Typically, suitable conveyor systems are either modular conveyor systems or made-to-order or custom conveyor systems.
Modular conveyors are commonly used in moving relatively low weight products or materials from one work area to another. A common environment for a modular conveyor is a molding environment where the modular conveyor carries the molded article from a molding operation to either a finishing, assembly or packaging center.
Chambers U.S. Pat. No. 5,131,531, which is incorporated by reference, discloses a modular conveyor formed by a series of modules, including a drive module, a straight module and an end module connected by various connectors that can maintain or change the elevation of the modules. The modules are supported above a floor by leg supports and define a frame about which a conveyor belt is supported. The conveyor belt is typically an endless belt.
One important advantage of the modular conveyor system is that the conveyor modules can be selected without the need for pre-assembly prior to shipping the conveyor to its ultimate destination, which dramatically reduces the assembly costs. Another advantage is that the modular conveyor is shipped unassembled in a relatively small container, which dramatically reduces the shipping cost. The modular nature of the pieces forming the modular conveyor lends the conveyor pieces to be made by any suitable molding process, negating the need for special tools to form or cut the pieces.
To effect a turn with the Chambers ""531 patent, two straight sections of the modular conveyor were angularly arranged, typically orthogonal to each other, and a deflecting bar, which can be curved or straight, was mounted between the adjacent side walls of the conveyors. Articles carried by the first conveyor contacted the deflecting bar and were subsequently deflected and/or pushed onto the second conveyor by the continued movement of the first conveyor alone or in combination with contact from subsequent articles on the first conveyor.
While satisfactory, the use of multiple conveyors in combination with a deflector to effect a turn was disadvantageous because the deflector inherently reduced the width of the conveyor along the turn and the articles carried by the conveyors typically did not maintain their initial spatial relationship as they piled up at the deflector, which is very important in some situations, especially timed assembly lines. The use of separate conveyors inherently required separate conveyor belts and separate drive systems all of which increased the complexity and cost of the conveyor.
Custom conveyors have the advantage that an exact conveyor shape can be made. One advantage of these systems is that a radius turn, e.g. a turn with a continuous arc, could be custom made, eliminating the need for a deflector. The radius turn also has the advantage of keeping the spacing of the articles carried by the conveyor. The flexibility in conveyor shape comes at substantially increased cost and complexity for the custom conveyors.
Since a majority of the pieces forming a custom conveyor must be specifically or individually made for a given conveyor, the custom conveyors tend to cost substantially more than the modular conveyors. The need for unique size pieces leads custom conveyors to be made from metal, instead of molded plastic elements as with the modular conveyors. The uniqueness of each design also requires that the conveyors be assembled and tested prior to shipping to their final destination. Often times, the assembled and tested custom conveyor must be partially or completely disassembled for shipping to the end destination. The shipping costs are also typically more expensive than the modular conveyors because of the unique sizes of many pieces of the custom conveyor.
Stand-alone radius turn assemblies are available and are typically used with custom conveyor systems. The stand-alone radius turn assemblies are made with a custom metal frame like the custom conveyors. Since these radius turn assemblies are stand-alone, they necessarily require their own belt or roller system and a corresponding drive mechanism, typically in the form of an electric motor, which disadvantageously increases their cost and complexity.
There is still a need for a modular conveyor that includes a modular radius turn, preferably made with modular components, to avoid the reduced volume and article stack-up encountered with the prior deflector-effected turns. A preferred modular conveyor may reap the manufacturing, assembling and shipping benefits of the modular components and would avoid, the disadvantages attendant the custom conveyors.
A conveyor assembly comprises a plurality of modular assemblies, each of which comprises a pair of side walls, cross members, and belt support. Fastener assemblies are provided for joining the modular assemblies to each other to form an assembled conveyor frame with the defined belt path. An endless conveyor belt having a length to fit in the defined belt path is also provided. According to the invention, at least one of the modular assemblies has sided walls that are bendable through an arc about an axis perpendicular to the belt path to define at least one radius turn of the belt path.
Preferably, the bendable side walls comprise a plurality of ribs positioned on the side walls to resist bending other than about the bending axis. The bendable side walls have opposing inner and outer surfaces connected by a peripheral edge. The inner surface faces the belt path when the conveyor frame is assembled and the ribs extend from the outer surface. The ribs are preferably spaced relative to each other along the side walls. A reduced thickness portion is formed in the side walls between at least some of the adjacent ribs for use in guiding the cutting of the side walls to adjust the length thereof. Preferably, the ribs are generally orthogonal to the longitudinal axis.
The bendable side walls can further comprise an embossment having an opening, with the embossment forming part of the fastener assembly. The embossment opening is preferably tapped and the fastener assemblies further comprise a plate for spanning between the embossment and the adjacent side wall. A threaded fastener can be received through an opening in the plate and threaded into the tapped opening to secure the plate to the adjacent side wall. The tapped opening can be formed by a threaded nut or the like that is received within the embossment opening. The embossments are preferably integrally formed with the side wall.
The conveyor assembly can further comprise a plurality of modular connectors for joining the modular assemblies end-to-end. The modular connectors preferably include side walls, cross members and belt supports. The modular connectors can be straight connectors or angular connectors. Preferably, the sum of the lineal length of the upper and lower edges of the side walls for the modular connectors are equal.
The at least one curve section preferably comprises an inner wall formed by the bendable side wall and defining an inner arc, and an outer wall formed by another bendable side wall and defining an outer arc. The outer arc has a radius of curvature greater than the inner arc. The side walls forming the inner wall and the outer wall preferably have a uniform length. One or both of the side walls forming the inner or outer wall can be cut to length to obtain the desired arc.
The modular assemblies can further comprise at least one of a motor assembly, a straight assembly, and a belt return assembly.
In another embodiment, the invention comprises a conveyor comprising a plurality of modular assemblies, each of which has a pair of spaced side walls, a cross member connecting the spaced side walls, and a belt support mounted on the cross member and forming at least a portion of a belt platform. Fastener assemblies join the modular assemblies to each other to form an assembled conveyor frame with a defined belt path. An endless conveyor belt is disposed within the belt path and is supported by the belt supports. At least one of the modular assemblies has bendable side walls bent through an arc about an axis perpendicular to the belt path to define at least one radius turn of the belt path.
The bendable side walls preferably have a longitudinal axis that is generally parallel to the belt path. A plurality of ribs can be positioned on the bendable side wall to resist bending about the longitudinal axis. The bendable side walls have opposing inner and outer surfaces connected by a peripheral edge. Preferably, the inner surface faces the belt path and the ribs extending from the outer surface. The ribs are preferably spaced relative to each other along the side wall. The side walls can have a reduced thickness portion located between the ribs for use in guiding the cutting of the side walls to adjust the length thereof. The ribs are preferably orthogonal to the longitudinal axis.
The bendable side walls can further comprise an embossment having an opening. The embossment can form part of the fastener assembly. Preferably, the embossment opening is tapped and the fastener assembly further comprises a plate spanning between the embossment and an adjacent side wall in combination with a threaded fastener received through an opening in the plate and threaded into the tapped opening to secure the plate to the bendable side wall. A threaded nut can be fixedly mounted within the embossment opening to form the tapped opening. At least one of the embossments is preferably integrally molded with the bendable side wall.
The conveyor can further comprise a plurality of modular connectors that join the modular assemblies end-to-end. The modular connectors preferably comprise side walls, cross members and belt supports. The modular connectors preferably comprise a straight connector or an angular connector.
The at least one radius turn preferably comprises an inner wall and an outer wall. Both the inner wall and outer wall are formed by at least one bendable side wall. The inner wall defines an inner arc and the outer wall defines an outer arc, which has a radius of curvature greater than the inner arc. The bendable side walls forming the inner wall and the outer wall initially are of a uniform length. At least one of the bendable side walls can be cut to a length less than the uniform length. At least one of the inner and outer walls is formed by multiple bendable side walls.
The endless conveyor belt is preferably formed from a single belt that contains the entire belt path. The modular assemblies can further comprise at least one of a motor assembly, a straight assembly, or a belt return assembly.
In yet another embodiment of the invention, a method for assembling a conveyor of modular assemblies into a conveyor with an endless belt path including a radius turn thereof, each of which modular assemblies comprises a pair of spaced side walls, a cross member connecting the spaced side walls, and a belt support mounted on the cross member and forming at least a portion of a belt platform, comprising the steps of bending the side walls through an arc about an axis perpendicular to the belt path to define at least one radius turn of the belt path. Further, the method includes the step of cutting the side walls to conform with the modular nature of the remaining modular assemblies. The method further comprises the step of assembling the modular assemblies together at facing edges thereof.
The a modular conveyor according to the invention includes a modular radius turn, preferably made with modular components, to avoid the reduced volume and article stack-up encountered with the prior deflector-effected turns. The modular conveyor according to the invention further reaps the manufacturing, assembling and shipping benefits of the modular components and avoids the disadvantages attendant the custom conveyors.